Vatican officials denied this week that Pope Francis is a target of ISIS, but the Italian government is stepping up security across the nation as it continues to collect intelligence on the growing terrorist group.

"There is nothing serious to this," spokesman the Rev. Federico Lombardi S.J. told Catholic News Agency in responding to a claim made by Italy's Il Tempo newspaper. "There is no particular concern in the Vatican. This news has no foundation."

Claiming the pope was under threat, the original Il Tempo report published Monday drew upon an unnamed source who said a number of Muslim jihadists had entered the country.

The source said the Islamic State, also known as ISIS or ISIL, considers the pope "the greatest exponent of the Christian religions" and the "bearer of false truth." Because of this, Islamic fundamentalists led by self-proclaimed Caliph Al-Baghdadi seek to "raise the level of confrontation" by putting Pope Francis "in the crosshairs."

The source did not say if the threat was a reaction to Pope Francis' admission earlier this month that "it is licit to stop the unjust aggressor," referring to U.S. airstrikes on ISIS in Iraq. At the time, the pope was rigorous with his comments, saying "I underscore the verb 'stop.' I don't say 'to bomb' or 'make war,' [but] 'stop.'"

While the Vatican says it remains unalarmed, several Italian news agencies said the government was nonetheless tightening security across the country.

The Daily Beast reported that deputy interior minister Filippo Bubbico is concerned about "sensitive targets" including the Vatican, embassies to both Italy and the Holy See, Catholic churches, transportation hubs, as well as historic landmarks like the Coliseum.

"ISIS poses an international and European security threat and we in Italy feel particularly exposed," Bubbico told Italian reporters at Sky News.

Italian newspaper Corriere della Sera reported that at least 50 Italians are known to be fighting with ISIS, most of them under the age of 25. Jihadi recruiter Imam Bilal Bosnic is said to have recruited many if not most of the fighters from Italy's northern regions.

Bosnic told La Repubblica in an interview published Thursday that James Foley, the American journalist publicly beheaded by ISIS, "was a spy" and called the killing "justified."

He also confirmed that the Vatican was a target.

"We Muslims believe that one day the whole world will be an Islamic state. Our goal is to make sure that even the Vatican will be Muslim. Maybe I will not be able to see it, but that time will come," he said.

Bosnic was investigated last year by Italian counterterrorism officials, and now resides in Bosnia.

Italy has recently waded into the ISIS conflict in Iraq, with parliament recently approving a measure to ship weapons to the country's Kurdish population. Kurdish peshmerga troops have also been assisted by the U.S. as they've fought back against encroaching ISIS fighters.